Some systems in may use an alternator for converting mechanical energy into electrical energy for powering a load. For example, most modern automobiles include an alternator that converts mechanical energy produced by a combustion engine to electrical energy that the alternator delivers to a twelve or twenty-four volt on-board power supply network (or “board net” for short) for powering one or more loads. Alternators are also commonly used in other vehicles and machinery.
An engine control unit (ECU) may manage power consumption of one or more loads drawing electrical power from a board net. The ECU may perform load balancing of the board net by monitoring variations in the current flowing through the rotating coil of the alternator (also referred to as “excitation current”) to determine the power of the alternator acting against the combustion engine or whether the alternator has any remaining capacity for powering any additional loads. Since monitoring the output current of the alternator directly may be a challenge for some automobile systems, an ECU may instead estimate the output current of an alternator using a model. However even finely tuned and calibrated models can be inaccurate in some situations. Without an accurate indication of the level of the current being output from the alternator, an ECU may be unable to perform accurate power management of the board net.